Device noise simulation

[emont89]

I'm simulating the noise of a circuit, but I want to use as an output variable not all the noise (represented by the VN2() function) but only the noise caused by a device (in this case the input transistor). Which method should I use?

 

[crutschow]

What are you using for a simulator?

 

[emont89]

I'm using cadence virtuoso

 

[crutschow]

I'm not familiar with that simulator but, if it's a Spice type simulator, the noise values for active devices are included in their models and should appear when you perform a noise analysis of the circuit. The output noise will then appear as a spectrum as determined by the bandwidth of the circuit.

 

[emont89]

Ok! Thanks for this answer. I have a further question. If I type VN() or VN2() as output variable I can see the total output noise of the circuit. There is a way for seeing not the total noise but only the noise of a single device creating an output variable (not using the noise summary for example). This would be very helpful for me in performing parametric analysis about the noise of a single device.

 

[crutschow]

Just measure the noise at the output node of the device.

If the device is in the middle of the circuit then you will have to measure the input noise and output noise, and subtract them to get the noise of the device.

 

[venkateshjuturu]

I'm not familiar with that simulator but, if it's a Spice type simulator, the noise values for active devices are included in their models and should appear when you perform a noise analysis of the circuit. The output noise will then appear as a spectrum as determined by the bandwidth of the circuit.

hai,
i am using T- spice simulator can u please explain step by step for calculating device noise
especially where i can get these values the noise values for active devices are included in their models and should appear when you perform a noise analysis of the circuit.

i am using ptm models 32nm sub-circuit model for FinFET (double-gate): V0.0

hope you will reply to me

thanks in advance

 

[Dominik Przyborowski]

In Virtuoso You are able to print noise rms value for N the most noises elements (results→print→noise summary) and also in result browser is possible to plot noise spectrum for each circuit element.

 

[venkateshjuturu]

In Virtuoso You are able to print noise rms value for N the most noises elements (results→print→noise summary) and also in result browser is possible to plot noise spectrum for each circuit element.

thanks for your reply
i got noise factor for a nmos device as 3k dB in cadence using 2 port (sp) analysis whether it is correct or not


but i need to know how to calculate the device noise using Tanner Spice using spice netlist

please help in this regard